Photo: In 2006 I went on a tour of Chicago via a chartered Chicago Transit Authority train. Part of the tour traveled along the Green Line. From above, you can see many of the trails people paved. Using Google Maps’ satellite imagery, I took a screen capture of 50th Street and King Drive and marked all of the unofficial walking paths I could see.

And, “it is an urban legend on many college campuses that many sidewalks and pathways were not planned at all, but paved by the university after students created their own paths from building to building, straying from those originally prescribed.”

Photo: From the top of University Hall, you can see all of the constructed diagonal paths surrounding the quad on the University of Illinois at Chicago’s East Campus. You can see at least four cemented “pathways of desire” in the photo.

You may also know these footpaths as “intention lines.”

Photo: A worn path or intention line through the snow in Ottawa, Ontario, Canada. Photo by Richard Akerman.